1. Field of the Invention
This invention relates to a conveying system for removing old roofing material from a roof preparatory to replacement with new roofing material.
2. Prior Art
Roofs of buildings are made with a variety of materials--tar paper, shingles, asphaltic tiles, etc. Because the roof surface is directly exposed to the weather, these coverings degrade so that after a period of time--generally twelve to twenty years, the roof covering must be replaced by new roofing material. The first step in replacing the roof is to tear off and remove the old weathered material ("tearoff"). Present practice is to tear off a portion of the old covering, carry it to the side of the building and drop it off onto the ground below. Use of conventional devices for carrying tearoff to the edge of the roof such as wheel barrows are not practical because of the pitch of the roof which renders the use of such devices awkward and dangerous. Furthermore, because material must be removed from large areas any, apparatus for conveying old material to the edge of the roof must be capable of being moved easily over a wide area, must be strong enough to support heavy loads, and must be constructed so that it can be adapted readily to various roof pitches.
There are many devices that have been built to convey a variety of materials. These devices include conveyor belts such as are used to convey goods and materials in factories and carts on tracks such as are used to haul ore from mines. However these conveying devices are built for use on flat surfaces, such as the floor of a factory (in the case of conveyor belts) or they have been built with permanent scaffolding and trestles (in cases such as cars on tracks used for hauling ore out of mines). Tracks of this type and associated supports have not been constructed so that they could be temporarily yet securely mounted at an arbitrary angle on a roof having a pitch occurring in a wide range.